Injecting data caching and other effects into the WCF pipeline

I have a service that always returns the same results for a given parameter. So naturally I would like to cache those results on the client.

Is there a way to introduce caching and other effect inside the WCF pipeline? Perhaps a custom binding class that could site between the client and the actual HTTP binding.

EDIT:

Just to be clear, I'm not talking about HTTP caching. The endpoint may not necessarily be HTTP and I am looking at far more effects than just caching. For exa开发者_Go百科mple, one effect I need is to prevent multiple calls with the same parameters.

The WCF service can use Cache-Control directives in the HTTP header to say the client how it should use the client side cache. There are many options, which are the part of HTTP protocol. So you can for example define how long the client can just get the data from the local cache instead of making requests to the server. All clients implemented HTTP, like all web browsers, will follow the instructions. If your client use ajax requests to the WCF server, then the corresponding ajax call just return the data from the local cache.

Moreover one can implement many interesting caching scenarios. For example if one set "Cache-Control" to "max-age=0" (see here an example), then the client will always make revalidation of the cache by the server. Typically the server send so named "ETag" in the header together with the data. The "ETag" represent the MD5 hash or any other free information which will be changed if the data are changed. The client send automatically the "ETag", received previously from the server, together inside the header of the GET request to the server. The server can answer with the special response HTTP/1.1 304 Not Modified (instead of the typical HTTP/1.1 200 OK response) and with the body having no data. In the case the client will safe to get the data from the local cache.

I use "Cache-Control:max-age=0" additionally with Cache-Control: private which switch off caching the data on the proxy and declare that the data could be cached, but not shared with another users.

If you want read more about caching control with respect of HTTP headers I'll recommend you to read the following Caching Tutorial.

UPDATED: If you want implement some general purpouse caching you can use Microsoft Enterprise Library which contains Caching Application Block. The Microsoft Enterprise Library are published on the CodePlex with the source code. As an alternative in .NET 4.0 you can use System.Runtime.Caching. It can be used not only in ASP.NET (see here)

I continue recommend you to use HTTP binding with HTTP caching if it only possible in your environment. In the way you could save many time of development and receive at the end more simple, scalable and effective application. Because HTTP is so important, one implemened already so much useful things which you can use out-of-the-box. Caching is oly one from the features.